Ultrahigh-Energy Neutrinos from Primordial Black Holes

The KM3NeT Collaboration recently announced the detection of a neutrino with energy 220 PeV. One possible source of such ultrahigh-energy particles is the rapid emission of energetic Hawking radiation from a primordial black hole (PBH) near the end of its evaporation lifetime. The mass distribution for PBHs features a power-law tail for small masses; a small subset of PBHs would be undergoing late-stage evaporation today. We find that recent high-energy neutrino events detected by the IceCube and KM3NeT Collaborations, with energies O(1-10^{2}) PeV, are consistent with event-rate expectations if a significant fraction of the dark matter consists of PBHs.